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● If sequence-number is not configured, the rules with the same order value are ordered according to
their configuration order.
● If sequence-number is configured, the sequence-number is used as a tie breaker for rules with the
same order.
When you use the log option, the CP processor logs details about the packets that match. Depending on
how many packets match the log entry and at what rate, the CP may become busy as it has to log these
packets’ details.
You cannot include IP, TCP, or UDP (Layer 3) filters in an ACL configured with ARP or Ether-type (Layer
2) filters. Apply Layer 2 ACLs to interfaces in Layer 2 mode.
When the configured maximum threshold is exceeded, generation of logs is stopped. When the interval
at which ACL logs are configured to be recorded expires, the subsequent, fresh interval timer is started
and the packet count for that new interval commences from zero. If ACL logging was stopped previously
because the configured threshold is exceeded, it is re-enabled for this new interval.
If ACL logging is stopped because the configured threshold is exceeded, it is re-enabled after the logging
interval period elapses. ACL logging is supported for standard and extended IPv4 ACLs, IPv6 ACLs, and
MAC ACLs. You can configure ACL logging only on ACLs that are applied to ingress interfaces; you
cannot enable logging for ACLs that are associated with egress interfaces.
You can activate flow-based monitoring for a monitoring session by entering the flow-based enable
command in the Monitor Session mode. When you enable this capability, traffic with particular flows
that are traversing through the ingress and egress interfaces are examined and, appropriate ACLs can
be applied in both the ingress and egress direction. Flow-based monitoring conserves bandwidth by
monitoring only specified traffic instead all traffic on the interface. This feature is particularly useful when
looking for malicious traffic. It is available for Layer 2 and Layer 3 ingress and egress traffic. You may
specify traffic using standard or extended access-lists. This mechanism copies all incoming or outgoing
packets on one port and forwards (mirrors) them to another port. The source port is the monitored port
(MD) and the destination port is the monitoring port (MG).
NOTE:
When ACL logging and byte counters are configured simultaneously, byte counters may
display an incorrect value. Configure packet counters with logging instead.
seq ether-type
Configure an egress filter with a specific sequence number that filters traffic with specified types of Ethernet packets. This
command is supported only on 12-port GE line cards with SFP optics. For specifications, refer to your line card documentation.
Syntax
seq sequence-number {deny | permit} ether-type protocol-type-number
{destination-mac-address mac-address-mask | any} vlan vlan-id {source-mac-
address mac-address-mask | any} [count [byte] [order] [log [interval
minutes] [threshold-in-msgs [count]] [monitor]
To remove this filter, use the no seq sequence-number command.
Parameters
sequence-
number
Enter a number from 0 to 4294967290.
deny Enter the keyword deny to drop all traffic meeting the filter criteria..
permit Enter the keyword permit to forward all traffic meeting the filter criteria.
destination-mac-
address mac-
address-mask
Enter a MAC address and mask in the nn:nn:nn:nn:nn format.
For the MAC address mask, specify which bits in the MAC address must match.
The MAC ACL supports an inverse mask; therefore, a mask of ff:ff:ff:ff:ff:ff allows
entries that do not match and a mask of 00:00:00:00:00:00 only allows entries that
match exactly.
any Enter the keyword any to match and drop specific Ethernet traffic on the
interface.
222 Access Control Lists (ACL)